The present invention relates to semiconductor devices and, more specifically, to control devices enabling storage of data in a fusebay arrangement.
In semiconductor chip manufacture, self-testing and self-repair systems are often included in a chip design. Such systems typically include a storage device, such as a fusebay, in which repair data may be stored and retrieved by a fusebay controller. The fusebay controller generally processes the repair data during storage and during retrieval, such as by applying compression during storage and decompression during retrieval.
All data stored into a fusebay should be retrievable in a reliable fashion. Typical techniques have focused on the use of digitally programmable sense thresholds to optimize the fuse programming process and to perform margin testing. While these techniques may provide robust fuse programming and sense with current fusebays, these techniques may not be as effective as fuse densities increase. In addition, because fuse sense circuits are increasingly being implemented in silicon-on-insulator (SOI) technologies, the floating body effect contributes to additional sense threshold variation. It is therefore more difficult to perform margin testing with complete assuredness and little impact on manufacturing yield. Further, advanced fuse storage macros include array structures in which many fuses may share a common bitline, which introduces variations in device leakage and data patterns, further contributing to fuse sense uncertainty.